CVE-2022-3112 in Linux
Summary
by MITRE • 12/15/2022
An issue was discovered in the Linux kernel through 5.16-rc6. amvdec_set_canvases in drivers/staging/media/meson/vdec/vdec_helpers.c lacks check of the return value of kzalloc() and will cause the null pointer dereference.
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Analysis
by VulDB Data Team • 03/05/2025
The vulnerability identified as CVE-2022-3112 represents a critical null pointer dereference flaw within the Linux kernel version 5.16-rc6 and earlier. This issue resides in the amvdec_set_canvases function located in the drivers/staging/media/meson/vdec/vdec_helpers.c file, which is part of the Meson video decoder driver subsystem. The vulnerability stems from inadequate error handling during memory allocation operations, specifically the failure to validate the return value of the kzalloc() function call. This oversight creates a scenario where the kernel driver continues execution even when memory allocation fails, leading to potential system instability and security implications.
The technical root cause of this vulnerability aligns with CWE-476, which describes null pointer dereference conditions in software development. The amvdec_set_canvases function performs memory allocation using kzalloc() to obtain memory for canvas structures required by the video decoder hardware. When kzalloc() fails to allocate memory, it returns a null pointer, but the function does not check this return value before proceeding with operations that assume valid memory allocation. This pattern violates fundamental kernel programming practices and creates a path for exploitation where an attacker could potentially trigger the null pointer dereference through malformed input or specific sequence of operations within the video decoding process.
The operational impact of CVE-2022-3112 extends beyond simple system crashes to potentially enable privilege escalation and denial of service conditions. Attackers could leverage this vulnerability to cause kernel panics or system reboots, effectively creating a denial of service scenario that disrupts video decoding operations on affected systems. The vulnerability is particularly concerning in embedded systems or devices that rely heavily on the Meson video decoder hardware, such as set-top boxes, media players, and other consumer electronics. From an attack perspective, this flaw maps to ATT&CK technique T1068, which involves exploiting legitimate credentials and privileges, as the vulnerability could be exploited to gain unauthorized access to system resources or escalate privileges within the kernel space.
Mitigation strategies for CVE-2022-3112 should focus on immediate code-level fixes and broader system hardening approaches. The primary remediation involves modifying the amvdec_set_canvases function to properly validate the return value of kzalloc() calls before proceeding with subsequent operations. This fix aligns with standard kernel security practices and follows the principle of defensive programming where all system calls and memory allocation operations must be validated for success before continuation. System administrators should prioritize applying kernel updates that contain the patched version of the driver, as the vulnerability affects the core kernel functionality and cannot be adequately mitigated through configuration changes alone. Additionally, implementing runtime monitoring and intrusion detection systems can help identify potential exploitation attempts targeting this specific vulnerability. The fix should also consider implementing proper error handling mechanisms that gracefully handle memory allocation failures, potentially logging the events for security analysis and ensuring system stability even when individual components fail. Organizations using affected Linux kernel versions should also review their kernel configuration options and consider disabling unnecessary video decoder drivers to reduce the attack surface.